Doing a good looking lettering job on the front panel of a homebrew project is always a challenge - especially if you're looking for something better than the usual dry transfer letters or Dymo labels. Several folks that have seen this project have asked about the lettering...so here's some info that may be useful.
The lettering was purchased on line from
http://doityourselflettering.com/ - an excellent site that allows one to create self stick vinyl lettering - the same as used by many sign shops. You spec out the lettering size, font (lots to choose from), and a host of special effects such as borders, drop shadow and curved text, etc. An interactive window updates your text to show your latest concoction. The process is simple and straightforward all the way through to completion of the order.
Just a quick note about saving money by doing your own 'weeding and taping'. The labels come off their machines between two pieces of clear thin acetate type material. The letters are cut but the extra material between the letters (and in the letters - like the hole in the letter "P") is still there. Basically, the weeding and taping process involves removing the top acetate (peels right off) and removing the extra material from between letters. This comes off as one long piece. An Exacto knife makes removing the extra material from within the letters easy. A strip of masking tape is then applied on top of the letters. To make placement of the letters in the next step simpler align the bottom of the tape with the bottom of the letters. Peel the masking tape and the letters are now stuck to the masking tape. I used blue masking because it was handy and it's possible to just see the letters through the tape which aid in placement. A thin brown masking tape might be a better choice.
Free handing the placement of the letters is probably not advisable - you only get one chance. I used a piece of masking tape stuck to the panel as a guide. The top of this piece of tape is where I wanted the bottom edge of the letters. Get this tape on the panel straight and your letters will be placed straight. Remember in the earlier step the bottom of the letters were aligned with the bottom of the 'transfer' tape. Now it's a simple matter to align the bottom of the 'transfer' tape with the the top of the tape used as a guide. Once the letters are in contact with the panel press lightly on each letter and carefully remove the masking tape. Use a piece of the discarded acetate to burnish the letters to the panel.
Some observations:
Do It Yourself Lettering will do the 'weeding and taping' for you but they get big $ to do it and the tape is not necessarily applied or cut straight. The orange letters used on this project are 0.4" tall and were a piece of cake to weed, tape and install. The white lettering is 0.15" tall and a bit more challenging...but the small lettering is dirt cheap so get a couple sets. Instead of ordering individual words for the small lettering I ordered one long string with double spaces in between words.
The lettering is designed to last a minimum of 5 years outdoors so it's pretty durable, but it's hard to say how it will stand up as panel lettering. The rack panel used for this project was a pre-painted black texture unit and the letters adhere very well. However, repeated fingernail contact would likely cause damage. A smooth panel would no doubt provide a better surface for the lettering and a layer of clear would offer further protection. Since the lettering isn't that expensive doing it over a number of years down the road wouldn't be that big a deal.
Apparently they can also work with graphics. Presumably one could do a dial type layout in a graphics program (like Adobe Illustrator) and have it made.
Needless to say there are many other uses for lettering. Suggest checking out the pictures in the 'testimonial' section. Playing around creating sample lettering costs nothing.
Info on the Pulse Width Modulator project can be found at:
http://www.w1vd.com/PWM.html 
